In this tutorial, we will learn writing Java program to calculate the square of a given number. Our program will take a number as an input and will return the square of that number as output.

## What is Square of Number?

When a number is multiplied to itself once, resultant number is known as square of number.

**For example:**

Suppose we want to calculate the square of 5.

**Square of 5** = 5^2 = 5*5 = 25.

## Program1: Calculate square of number in Java

In this program we have applied straightforward approach. Here we are taking the input number from the user and calculating the square using a simple mathematical expression (`num * num`

). After calculating the result, we are printing it on the console. The output for the input 5 was correctly computed and printed as 25.0.

```
import java.util.*;
public class Main
{
public static void main(String[] args) {
float num,square;
Scanner sc = new Scanner(System.in);
System.out.println("Please give the number to calculate square");
num= sc.nextFloat();
square = num*num;
System.out.println("Square of "+num+" is ");
System.out.printf("%.2f", square);
}
}
```

**Output**

```
Please give the number to calculate square
5
Square of 5.0 is
25.00
```

**Explanation**

For input 5, the output generated by our program is 5.0*%.0 i.e. equals 25.0.

## Program 2: Calculate Square using Java 8

In this program we are using Java 8 streams to calculate the square of a number. The `DoubleStream.of(num).map(x -> x * x)`

expression is used here to find square of a given input number. And the result is printed using the `findFirst`

operation. The output for the input 6 is correctly computed and printed as 36.0.

```
import java.util.*;
import java.util.stream.*;
public class Main
{
public static void main(String[] args) {
float num;
double square;
Scanner sc = new Scanner(System.in);
System.out.println("Please give the number to calculate square");
num= sc.nextFloat();
square = DoubleStream.of(num)
.map(x -> x * x)
.findFirst()
.orElse(Double.NaN);
System.out.println("Square of "+num+" is ");
System.out.printf("%.2f", square);
}
}
```

**Output**

```
Please give the number to calculate square
6
Square of 6.0 is
36.00
```

## Conclusion

In this tutorial you have learnt writing Java programs to calculate the square of a given number. The square of a number is calculated by multiplying the number by itself once.

**Program 1: Calculate Square of a Number in Java**

In the first program we have used straightforward logic to calculate the square of number. We have multiplied input number to itself to calculate the square of a number,. At the last we have printed the output. The mathematical expression (`num * num`

) is used to calculate the square. The result was then printed to the console. The output for the input 5 was correctly computed as 25.0.

**Program 2: Calculate Square using Java 8**

In the second program we have used the Java 8 streams. The `DoubleStream.of(num).map(x -> x * x)`

expression is applied to find the square of the input number. The result was obtained using the `findFirst`

operation. For the input 6, output was correctly computed as 36.0.

Hope above tutorial helped you to understand writing Java program to calculate the power of a given input number.

Happy coding!